Strategy: It’s a new country and I’d like to spend a little time there. Visas: U.S. citizens receive a 90-day entry permit on arrival. Jeju Island stays are visa free for 5 days. Jeju Island get me another country. Note the flights to Jeju and back.
Weather: Temperature averages for lows/highs is 46/65 with less than 1/8th inch of rain in April. Oklahoma City gets about 3 inches of rain in April.
Airfare: Inchon is a good place to sleep. Seoul flights from Okinawa look to be $85 USD on Jeju Air. I checked Jetstar Japan and found there were no flights listed from Okinawa to Tokyo in April but there were flights listed in March for $85 USD. I’m thinking that it’s too early (09/2016) to book flights out in this area for April.
Transfers: 1,000.00 KRW = 0.906110 USD. Lots of ways to get to Seoul. Excellent guide is here.
Hostels: HostelWorld. Hostelbookers. Over 100 hostels listed in Seoul. Prices in the teens.
Attractions: TripAdvisor. VirtualTourist. Google. Lonely Planet. The Hillman Wonders of South Korea are the Bulguksa Temple (blue) and 8 reds: Changdeokgung Palace & Secret Garden Seoul), Jongmyo Royal Shrine (Seoul), Haeinsa Temple, Gyeongbokgung Palace (Seoul), Kyongju Tombs & Museum, Mt Sorak Hiking Trails, Beopjusa Temple and Sokkuram Grotto. Think N Seoul Tower, Namdaemun Market, Myeong-dong, Fortress Wall of Seoul, Lotte World, Insadong, Cheonggyecheon Stream, The War Memorial of Korea, Bukchon, Noryangjin Fish Market, Gwangjang Market, 63 City,
Food: Tosokchon Samgyetang, See this article for more. And here. and here.